CAJ | 학술논문

目的评价后凸成形骨水泥(Polymethylmethacrylate,PMMA)强化技术对骨质疏松情况下骶骨钉固定强度的生物力学影响,为骶骨钉松动选择坚强的补救技术提供依据.方法 11具新鲜骶骨标本用于实验,并采用DEXA评价标本骨密度.在同一骶骨标本上,依次建立非PMMA强化和PMMA强化骶骨钉的固定模型如下,A组:单皮质椎弓根钉;B组:双皮质椎弓根钉;C组:传统PMMA强化单皮质椎弓根钉;D组:后凸成形PMMA强化椎弓根钉;E组:后凸成形PMMA强化侧翼钉.在MTS试验机上对五种骶骨钉依次进行轴向拔出测试,记录最大拔出力并比较.结果 11具标本的平均骨密度为0.71±0.08 g/cm~2.A组的螺钉拔出力(508 N)显著低于其他4种固定组(P＜0.05).B组的螺钉拔出力(685 N)与E组(702 N)无显著差异(P＞0.05),但是,两者的拔出力均显著低于C和D组(P＜0.05).重要的是,D组(986 N)的拔出力显著高于C组(846 N).结论在骨质疏松患者的骶骨同定中,双皮质骶骨椎弓根钉较单皮质具有显著的力学优势.骶骨椎弓根钉一旦发生松动,传统的和后凸成形PMMA强化技术均可成为补救手段,并且后凸成形PMMA强化骶骨椎弓根钉可获得最坚强的锚定.
목적 평개후철성형골수니(Polymethylmethacrylate,PMMA)강화기술대골질소송정황하저골정고정강도적생물역학영향,위저골정송동선택견강적보구기술제공의거.방법 11구신선저골표본용우실험,병채용DEXA평개표본골밀도.재동일저골표본상,의차건립비PMMA강화화PMMA강화저골정적고정모형여하,A조:단피질추궁근정;B조:쌍피질추궁근정;C조:전통PMMA강화단피질추궁근정;D조:후철성형PMMA강화추궁근정;E조:후철성형PMMA강화측익정.재MTS시험궤상대오충저골정의차진행축향발출측시,기록최대발출력병비교.결과 11구표본적평균골밀도위0.71±0.08 g/cm~2.A조적라정발출력(508 N)현저저우기타4충고정조(P＜0.05).B조적라정발출력(685 N)여E조(702 N)무현저차이(P＞0.05),단시,량자적발출력균현저저우C화D조(P＜0.05).중요적시,D조(986 N)적발출력현저고우C조(846 N).결론 재골질소송환자적저골동정중,쌍피질저골추궁근정교단피질구유현저적역학우세.저골추궁근정일단발생송동,전통적화후철성형PMMA강화기술균가성위보구수단,병차후철성형PMMA강화저골추궁근정가획득최견강적묘정.
Objective To evaluate the biomechanical effect of kyphoplasty-assisted polymethylmethacrylate (PMMA) augmented technique on the sacral screw fixation strength in osteoporotic sacrum,and guide the use of rigid salvage technique for loosened sacral pedicle screw.Methods 11 fresh osteoporotic cadaveric sacra were used in this study.Following measurement of the bone mineral density (BMD) of each specimen with dual-energy radiograph absorptiometry,two pedicle screws and three salvage techniques with PMMA augmentation were sequentially established and tested on the same sacrum as follows,Group A:unicortical pedicle screw;Group B:bicortical pedicle screw;Group C:pedicle screw with traditional PMMA augmented technique;Group D:pedicle screw with kyphoplasty-assisted PMMA augmentation;Group E:ala screw with kyphoplasty-assisted PMMA augmentation.Axial pull-out resistance of each screw was sequentially tested on a MTS material testing machine,and the maximum pull-out strengths were measured and compared.Results The average BMD of 11 specimens was 0.71±0.08 g/cm~2.Group A (508 N) exhibited significantly lower pull-out strength compared with all the other groups (P＜0.05).No statistical difference on pull-out strength was detected between Group B (685 N) and E (702 N) (P＞0.05);however,the two techniques exhibited markedly lower pull-out strength than Group C and D (P＜0.05).Importantly,the pull-out strength in Group D (986 N) was obviously higher than that in Group C (846 N).Conclusion For sacral screw fixation of osteoporotic patient,bicortical pedicle screw could acquire significantly higher fixation strength than the unicortical.Once the loosening of pedicle screw occurs,the traditional and kyphoplastyassisted PMMA augmentations may serve as a suitable salvage technique.Moreover,the sacral pedicle screw with kyphoplasty-assisted PMMA augmented technique may obtain the strongest anchoring.